Limits...
Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis.

da Silva VM, Carter AM, Ambrosio CE, Carvalho AF, Bonatelli M, Lima MC, Miglino MA - Reprod. Biol. Endocrinol. (2007)

Bottom Line: However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries.The endometrium was well vascularised and richly supplied with actively secreting glands.These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Institute of Amazonian Research, Manaus, AM, Brazil. tucuxi@inpa.gov.br

ABSTRACT
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

Show MeSH

Related in: MedlinePlus

Placentation in the boto, Inia geoffrensis. The glandular endometrium forms trabeculae lined with uterine epithelium. Branched chorionic villi are inserted into the crypts. The spaces between the trophoblast and uterine epithelium are likely shrinkage artefacts. H.E. Scale bar = 1000 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC1919380&req=5

Figure 4: Placentation in the boto, Inia geoffrensis. The glandular endometrium forms trabeculae lined with uterine epithelium. Branched chorionic villi are inserted into the crypts. The spaces between the trophoblast and uterine epithelium are likely shrinkage artefacts. H.E. Scale bar = 1000 μm.

Mentions: The interhemal membrane was of the epitheliochorial type. The uterine trabeculae interdigitated with folds of allantochorion that bore the fetal villi (Figure 4). Spaces occurred between the trophoblast and uterine epithelium. As discussed below, they likely were shrinkage artefacts.


Placentation in dolphins from the Amazon River Basin: the Boto, Inia geoffrensis, and the Tucuxi, Sotalia fluviatilis.

da Silva VM, Carter AM, Ambrosio CE, Carvalho AF, Bonatelli M, Lima MC, Miglino MA - Reprod. Biol. Endocrinol. (2007)

Placentation in the boto, Inia geoffrensis. The glandular endometrium forms trabeculae lined with uterine epithelium. Branched chorionic villi are inserted into the crypts. The spaces between the trophoblast and uterine epithelium are likely shrinkage artefacts. H.E. Scale bar = 1000 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1919380&req=5

Figure 4: Placentation in the boto, Inia geoffrensis. The glandular endometrium forms trabeculae lined with uterine epithelium. Branched chorionic villi are inserted into the crypts. The spaces between the trophoblast and uterine epithelium are likely shrinkage artefacts. H.E. Scale bar = 1000 μm.
Mentions: The interhemal membrane was of the epitheliochorial type. The uterine trabeculae interdigitated with folds of allantochorion that bore the fetal villi (Figure 4). Spaces occurred between the trophoblast and uterine epithelium. As discussed below, they likely were shrinkage artefacts.

Bottom Line: However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries.The endometrium was well vascularised and richly supplied with actively secreting glands.These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

View Article: PubMed Central - HTML - PubMed

Affiliation: National Institute of Amazonian Research, Manaus, AM, Brazil. tucuxi@inpa.gov.br

ABSTRACT
A recent reassessment of the phylogenetic affinities of cetaceans makes it timely to compare their placentation with that of the artiodactyls. We studied the placentae of two sympatric species of dolphin from the Amazon River Basin, representing two distinct families. The umbilical cord branched to supply a bilobed allantoic sac. Small blood vessels and smooth muscle bundles were found within the stroma of the cord. Foci of squamous metaplasia occurred in the allanto-amnion and allantochorion. The interhemal membrane of the placenta was of the epitheliochorial type. Two different types of trophoblastic epithelium were seen. Most was of the simple columnar type and indented by fetal capillaries. However, there were also areolar regions with tall columnar trophoblast and these were more sparsely supplied with capillaries. The endometrium was well vascularised and richly supplied with actively secreting glands. These findings are consistent with the current view that Cetacea are nested within Artiodactyla as sister group to the hippopotamids.

Show MeSH
Related in: MedlinePlus